Bicycle-gearing.



' No. 633449... Patented sept..|9, |899.I

E. A. UAKMAN.

BlcYcLE GEAmNa.

(Application led Nov. 15, 1597. Renewed Feb. 3, 1899.) (No Model.) 2Sheets-Sheet l.-

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No. 63.3,|49. Patented sept. 19, |899.

E. A. oAKMAN. A

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(Application filed Nov. 15, 1897. Renewed Feb. 3, 1899.)

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(No Model.)

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UNITED VSTATES PATENT OFFICE.

ERVVIN A. OAKMAN, OF OHAPPELLS, SOUTH CAROLINA.`

BICYCLE-GEARING.

SPECIFICATION forming part of Letters Patent No. 633,149, datedSeptember 19, 1899. Application filed November 15, 1897. RenewedFebruary 3, 18.99. Serial No. 704,433. (No model.)

T0 a/ZZ whom it 'ma/y con/cern: n

Be it known that I, ERWIN A. OAKMAN, a citizen of the United States,residing at Chappells, inthe county of Newberry andState of SouthCarolina, have invented certain new and useful Improvements inBicycle-Gearing; and I do hereby declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

My invention relates to improvements in bicycle-driving mechanism; andit consists of the novel features hereinafter described and claimed.

Referring tothe accompanying drawings, in which the same letters ofreference designate the same parts in the several views,` Figure 1represents a side elevation of a bicycle with myimproved drivingmechanism applied thereto. Fig. 2 Yrepresents a vertical -sectional viewtaken on the line 2 2 of Fig. l looking rearwardly. Fig. 3 represents ahorizontal section through the Vrear hub and bearings, taken on the-line3 3 of Fig. 'l. Fig. Li represents a side elevation of the rear-forkconnection. Fig. 5 represents a side elevation of the ball-clutch withone of the side disks removed. Fig. 6 is a sectional view of the same,taken on the line 6 6 of Fig. 7, with the center diskreinoved. Fig. 7 isa vertical sectional View through the clutch, taken on the line 7 7 ofFig. 6, showing the three'disks in their relative positions. Fig. 8 is ahorizontal sectional view through a modified form of clutch.

A designatesthe frame of a bicycle of the usual construction with theexception that the crank-han ger is omitted and a special form ofrear-fork connection B is used. The rearfork connection B is formed ofaforgin g bifurcated at its rear end to form the two parallel arms b,which are grooved, as at o', to form guides for the bearing-block C, andthe said arms b are connected at their rear ends by a cross-piece D,provided with lugs d to engage transverse slots b2 in the arms l) andhooked, as at d', to take over the ends of the said arms b to preventthe latter from spreading apart. An adjusting-screwD is arrangedsuitable means.

in a threaded opening in the cross-piece D vand enters an opening in thebearing-blockC for the purpose of adjusting the said bearingblock, andwith itthe axle of the rear wheel. The bearing-block O is provided witha screwthreaded opening therethrough in which is arranged a pair ofrings c, forming an adjustable ball-race for the balls e, which supportthe axle. On the forward end of the rearfork connection B is formedaround shank B to iit the rear horizontal tubing a, and anupwardly-projecting shank B2 is formed on the said connection to t therear-fork tube a. The shanks B and B2 are placed in the tubin'gct and0.', respectively, and secured by any In one of the rear-forkconnections B is formed a bearing B3 for a purpose to be hereinafterexplained. The axle F is provided with sleeves f, around which areformed races for the balls e, and the in ner ends of the said sleevesare enlarged to form cones for the balls e', upon-which the rear wheel Aturns upon the axle F, the hub A2 of the said rear wheel being providedwith ball-races Ca2 for the said balls c'.

From the foregoing it will be seen that lthe rear wheel A is free toturn upon the axle F, and the latter is also free to turn in thebearings in the blocks O. Near each end of the axle F is rigidlysecured, by a key or other suitable means, a disk F.

The levers H are formed with rings H at their rear ends, and the saidrings are provided with ball-races h to receive the balls e2, which whenthe parts are in their normal positions are arranged around theperiphery of the disks F', as shown in Fig. 5 of the drawings, thusallowing the disks F to revolve freely within the rings H. The rings Hare open, as at H2, to allow the insertion of the balls, the saidopenings being closed by pieces h2, which are turned to correspond withthe ball-race and held in position by the bolts h2, which pass throughthe said pieces h2 and through the lugs h4 on the rings H', as shown inFigs. 5 and 6. Disks I are placed on each side of the rings H' and areheld in position by bolts 7l, which pass through the said disks andrings, thus holding the several parts firmly together. The disks I areprovided with a number of recesses I' around their inner surfaces, intowhich recesses are ttcd IOO hardened-steel blocks I2, having taperedslots 'i2 for the reception of the balls e5. These slots are so arrangedin the disks that when the levers H are in their raised positions theshallow ends of the slots all point downwardly approximately at rightangles t0 the line which designates the horizontal line when the leversare in their raised positions, as shown in Fig. G. The upper ends of theslot-s are deep enough to allow the balls when in the deeper' ends toremain loosely against the central disks F' without binding. When thelever is in its raised position,the balls will gravitate toward thelower ends of the slots until they bind against the sides of the disksF' and opposite to eachother, whereby none remain loose to rattle, asshown in Fig. 7, when the depression of one of the levers H will rotatethe disk F' on the same side of the bicycle and with it the axle. As thelever is raised the balls e will be rolled into the deeper ends of theslots, and thus allow the ring H and the disk I to turn freely on thedisk F and axle. Of course it is evident that other forms of clutches aswell as the gravity-clutch may be used. For instance, instead of havingthe races of the balls e3 straight and vertically arranged, they may becurved and the balls held to their proper position by springs. Otherequivalent forms will doubtless suggest themselves to others skilled inthe art.

On the axle F, just out-side of one of the rear-fork connections B, isrigidly mounted a gear-wheel F2, which meshes with a pinion 7s on a'short shaft K, mounted in ball-bearings in the bearing B3 of the saidrear fork connection. On the other end of the short shaft K is mounted agear-wheel 7s', meshing with a pinion a4 on the hub A2 of the rear wheelA of the bicycle. rlhus the rotation of the axle will be transmittedirst to the shaft K and then to the hub of the wheel, the speedincreasing with each transmission, according to t-he relative sizes ofthe several gearwheels used. These gear-wheels are shown on the drawingsmuch larger in proportion to the driving-wheel than they are in practicefor clearness of illustration.

The two levers H are connected together by rods L and a chain L', whichlatter passes overa suitable wheel nl, mounted in a bracket M on therear-fork tubes a', as shown in Figs. I and 2 of the drawings. By thisconstruction it will be seen that when one lever is depressed the otherlever will be raised. The levers H are provided at. their forward endswith pedals H3, which I prefer to form with a concave portion 71.5 forthe ball of the foot and with an extension 7L for the heel; but anyother form of pedal may be used, if preferred.

The operation of the device is as follows: Then one lever is presseddown, the balls e3 will clutch on opposite sides of the disk F' androtate the said disk and axle in the direction to turn the wheelforwardly, the motion being transmitted through the train of gearing tothe rear wheel of the bicycle. At the same time the other lever will beraised by the action of the rods L and chain L', as will be readilyunderstood. Vhen the other lever is depressed, the axle will again beturned forwardly while the first lever is being raised. Thus the rearwheel A of the bicycle will be continuously driven forward by thedownward motion of the two levers acting alternately. Consequently thelevers have a perfect and instantaneous control over the driving-axle atevery point of its revolution, so that dead-centers will not occur. Inlieu of the chain and rods for raising the levers I may use a springarranged in any suitable manner, in which case both of the levers wouldremain normally in the raised position.

By forming the slots i2 in the hardened*- steel blocks I2 it will beobvious that should a slot become worn or indented the block may beeasily removed and a new one inserted in its place, thus making the lifeof the disks much longer; but should it be found desirable in practice Imay form the slots directly in the disks which may be sufficientlyhardened to withstand the pressure of the balls at the time the clutchis in operation.

In Fig. 8 is shown a modification of the clutchin which the ring II isdispensed with, the clutch being formed of two members N and N boltedtogether and inclosing the disk FC In this instance the ball-race h isturned half in each member of the clutch and the slots for the balls e3may be formed either in the members themselves or in the hardenedblocks, as hereinbefore described. The lever H is formed integral withor secured to one of the members. It is obvious that the clutch shownmay be used not only in connection with a bicycle, but also inconnection with various other forms of machinery.

Having thus described my invention, what I claim, and desire to secureby Letters Patent of the United States, is-

l. A clutch, consisting of a shaft, a disk rigidly mounted on saidshaft, external disks arranged parallel to said disk and provided withslots on their inner faces and balls mounted in said slots and arrangedso as to press at opposite points on the faces of said internal disk,substantially as described.

2. In a bicycle driving-gear the combination with an axle mounted torotate in the frame, and disks rigidly mounted on the said axle, ofclutches inclosing the said disks, balls mounted in the said clutches topress against the faces of said disks at opposite points, and means forturning the said clutches, substantially as described.

3. In a bicycle driving-gear the combination with an axle mounted torotate in the frame, and disks rigidly mounted on the said axle, ofclutches inclosing the said disks, blocks having tapering slots mountedin recesses in the said clutches balls in the said slots to IOO IIO

Io points on the faces of said disks, levers for operating said clutchesand a cord or chain connecting said levers, and passing over a part ofthe frame, substantially as described.

In testimony whereof I affix my signature in presence of two Witnesses.

ERWN A.' OAKMAN.

Witnesses:

L. M. RAGIN, JAMES M. GIBBs.

